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The endophytic Basidiomycete Sporobolomyces ruberrimus protects its host Arabidopsis arenosa against metal toxicity. Plants inoculated with the fungus yielded more biomass and exhibited significantly fewer stress symptoms in medium mimicking mine dump conditions (medium supplemented with excess of Fe, Zn and Cd). Aside from fine-tuning plant metal homeostasis, the fungus was capable of precipitating Fe in the medium, most likely limiting host exposure to metal toxicity. The precipitated residue was identified by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-Ray Diffraction (XRD) and electron microscopy (SEM/TEM) with energy dispersive X-Ray analysis (EDX/SAED) techniques. The performed analyses revealed that the fungus transforms iron into amorphous (oxy)hydroxides and phosphates and immobilizes them in the form of a precipitate changing Fe behaviour in the MSR medium. Moreover, the complexation of free Fe ions by fungi could be obtained by biomolecules such as lipids, proteins, or biosynthesized redox-active molecules.

Toxic metal pollution requires significant adjustments in plant metabolism. Here, we show that the plant microbiota plays an important role in this process. The endophytic Sporobolomyces ruberrimus isolated from a serpentine population of Arabidopsis arenosa protected plants against excess metals. Coculture with its native host and Arabidopsis thaliana inhibited Fe and Ni uptake. It had no effect on host Zn and Cd uptake. Fe uptake inhibition was confirmed in wheat and rape. Our investigations show that, for the metal inhibitory effect, the interference of microorganisms in plant ethylene homeostasis is necessary. Application of an ethylene synthesis inhibitor, as well as loss-of-function mutations in canonical ethylene signalling genes, prevented metal uptake inhibition by the fungus. Coculture with S. ruberrimus significantly changed the expression of Fe homeostasis genes: IRT1, OPT3, OPT6, bHLH38 and bHLH39 in wild-type (WT) A. thaliana. The expression pattern of these genes in WT plants and in the ethylene signalling defective mutants significantly differed and coincided with the plant accumulation phenotype. Most notably, down-regulation of the expression of IRT1 solely in WT was necessary for the inhibition of metal uptake in plants. This study shows that microorganisms optimize plant Fe and Ni uptake by fine-tuning plant metal homeostasis.

Ecological methods are becoming increasingly popular. One of these methods is plant biotization. In our paper, we focus on selection of Vaccinium corymbosum hairy root-inhabiting fungi for plant growth promotion in a single microorganism inoculation setup and then composed a multiorganismal inoculum enriched with a representative of another group of fungi, leaf endophytes. The hairy roots of V. corymbosum hosted 13 fungal taxa. In single inoculation of the plant with fungal strains, the most beneficial for plant growth were Oidiodendron maius and Phialocephala fortinii. Additional inoculation of the plants with three root symbiotic fungi (O. maius, Hymenoscyphus sp. and P. fortinii) and with the endophytic fungus Xylaria sp. increased plant height in laboratory experiments. On a semi-industrial scale, inoculation improved plant biomass and vitality. Therefore, the amendment of root-associated fungal communities with a mixture of ericoid mycorrhizal and endophytic fungi may represent an alternative to conventional fertilization and pesticide application in large-scale blueberry production. KEY POINTS: • O. maius and P. fortinii significantly stimulated V. corymbosum growth in a single inoculation. • Multimicroorganismal inoculum increased plant biomass and vitality. • Blueberry biotization with ericoid and endophytic fungi is recommended.

Our observations of predatory fungi trapping rotifers in activated sludge and laboratory culture allowed us to discover a complicated trophic network that includes predatory fungi armed with bacteria and bacteriophages and the rotifers they prey on. Such a network seems to be common in various habitats, although it remains mostly unknown due to its microscopic size. In this study, we isolated and identified fungi and bacteria from activated sludge. We also noticed abundant, virus-like particles in the environment. The fungus developed absorptive hyphae within the prey. The bacteria showed the ability to enter and exit from the hyphae (e.g., from the traps into the caught prey). Our observations indicate that the bacteria and the fungus share nutrients obtained from the rotifer. To narrow the range of bacterial strains isolated from the mycelium, the effects of bacteria supernatants and lysed bacteria were studied. Bacteria isolated from the fungus were capable of immobilizing the rotifer. The strongest negative effect on rotifer mobility was shown by a mixture of Bacillus sp. and Stenotrophomonas maltophilia. The involvement of bacteriophages in rotifer hunting was demonstrated based on molecular analyses and was discussed. The described case seems to be an extraordinary quadruple microbiological puzzle that has not been described and is still far from being understood.

Forest soils are being exposed to nutrient deficiency and acidification at increasing rates as a result of intensive management. Mineral fertilization, however, provides a way to improve soil nutrient balance. The aim of this study is to present the effects of mineral fertilization on the properties of forest soil 11 years after fertilization. Our research investigated the effects of dolomite, magnesite and serpentinite fertilization on the physicochemical properties of the soil, soil biological activity, and fungal diversity. We also determined the condition of a new generation of fir trees after mineral fertilization. In autumn, 2008, fertilizers (dolomite, magnesite and serpentinite, specifically) in the amount of 4000 kg.ha−1 were added to plots in the Wisla Forest District in Poland; one area was left unfertilized to act as the control area for this research. Our results reveal that all fertilization improved the selected soil's physicochemical properties (pH, Ca and Mg content) and accordingly, its biochemical activity; in particular, we found that dolomite (4000 kg.ha−1) contributed heavily to soil improvement. The findings also showed that soil pH and calcium content were strongly dependent on enzymatic activity, while dolomite fertilization resulted in a significant increase in biomass size in the fir trees included in this study. In addition to being associated with the highest plant biomass and amounts of enzymatic activity, dolomite-fertilized soil also had the highest number of fungal operational taxonomic units (OTUs): 403, compared to 322 OTUs in the control soil. Finally, the fungal communities in the control soil varied significantly from the fungal communities in soils fertilized with dolomite and serpentinite. The results of this research support mineral fertilization, and in particular, fertilization using dolomite in amounts of 4000 kg.ha−1, to improve soil nutrient supply and to shape the biological activity expressed by the enzymatic activity of forest soils.

The role of endophytic fungi isolated from different populations of European Ni hyperaccumulators was investigated in regard to the microorganisms' ability to enhance the hyperaccumulation of Ni in Noccaea caerulescens. Effects of particular species of endophytic fungi on adaptation of N. caerulescens to excess Ni were tested by co-cultivation with single strains of the fungi. Seven of these had a positive effect on plant biomass production, whereas two of the tested species inhibited plant growth; biomass production of inoculated plants was significantly different compared to non-inoculated control. Inoculation with six fungal strains: Embellisia thlaspis, Pyrenochaeta cava, Phomopsis columnaris, Plectosphaerella cucumerina, Cladosporium cladosporioides and Alternaria sp. stimulated the plant to uptake and accumulate more Ni in both roots and shoots, compared to non-inoculated control. P. columnaris was isolated from all plant species sampled. Strains isolated from Noccaea caerulescens and Noccaea goesingensis increased Ni root and shoot accumulation of their native hosts (compared to non-inoculated control). Inoculation of different populations of Noccaea with P. columnaris of foreign origin did not cause its host to accumulate more Ni, with the exception of the Ni-unadapted ecotype of N. goesingensis. Inoculation with P. columnaris from N. caerulescens significantly improved Ni uptake, but the effect of the fungus was not as prominent as in the case of N. caerulescens. By comparing the transcriptomes of N. caerulescens and N. goesingensis from Flatz inoculated with P. columnaris, we showed that enhanced uptake and accumulation of Ni in the plants is accompanied by an upregulation of several genes mainly involved in plant stress protection and metal uptake and compartmentation.

The role of an endophytic Zygomycete Mucor sp. in growth promotion and adaptation of the photosynthetic apparatus to increased energy demands of its hosts Arabidopsis arenosa and Arabidopsis thaliana was evaluated. Inoculation with the fungus improved the water use efficiency of the plants and allowed for them to utilize incident light for photochemistry more effectively by upregulating the expression of several photosystem I- and II-related genes and their respective proteins, proteins involved in light harvesting in PSII and PSI and carbon assimilation. This effect was independent of the ability of the plants to acquire nutrients from the soil. We hypothesize that the accelerated growth of the symbiotic plants resulted from an increase in their demand for carbohydrates and carbohydrate turnover (sink strength) that triggered a simultaneous upregulation of carbon assimilation. Arabidopsis plants inoculated with Mucor sp. exhibited upregulated expression in several genes encoding proteins involved in carbohydrate catabolism, sugar transport, and smaller starch grains that indicate a significant upregulation of carbohydrate metabolism.

The aim of this study was to assess the biodiversity of endophytic fungi from Arabidopsis arenosa growing on a post mining waste dump and to evaluate their role in plant adaptation to metal toxicity. Severeal of the fungi were beneficial for the plant. Among them, a fungus belonging to the Mucor genus, was found to interact with a broad range of plants, including Brassicaceae metallophytes. Mucor sp. was shown to be highly tolerant to elevated levels of Zn, Cd, and Pb and to accelerate plant-host growth under either toxic-metal stress or control conditions. When inoculated with Mucor sp., A. arenosa under toxic-metal stress acquired more N and showed significantly down-regulated catalase activity, which suggests suppression of toxic-metal-induced oxidative stress. We used the model plant-A. thaliana to evaluate the dynamics of plant-tissue colonization by the fungus as monitored with qPCR and to analyze the host's transcriptome response during early stages of the interaction. The results revealed the induction of a plant-defense and stress-related response on the 5th day of co-culture, which was in accord with the decrease of fungal abundance in shoots on the 6th day of interaction. Presented results demonstrate the importance of endophytic fungi in plant toxic-metal tolerance.

The endophytic fungus Mucor sp. was isolated from Arabidopsis arenosa inhabiting post mining wastes lands. Its role in plant adaptation to toxic metal enriched environment was evaluated. Plants inoculated with the fungus yielded significantly more biomass. Their growth response was correlated with significant elongation of root hairs, an improved water and P status and a significant upregulation of the expression of genes associated with nutrient uptake. The mechanism of root hair elongation was investigated with auxin and ethylene insensitive Arabidopsis thaliana mutants. The results clearly indicate that the root hair elongation phenotype results from fungi induced alterations in ethylene metabolism. The upregulation of close to 50 genes associated with ethylene biosynthesis and signaling confirm these results. The accumulation of Zn and Fe was lower in endophyte inoculated plants. Additionally, root to shoot translocation of Fe, Cd and Zn was improved. The expression of metal transporters associated with metal influx, efflux and distribution within the plant corresponded with altered metal homeostasis. The results of this study clearly show that the endophytic fungus plays an important role in the adaptation of the non-mycorrhizal A. arenosa to metal toxicity.

Phytoremediation of polluted sites can be improved by co-inoculation with mycorrhizal and endophytic fungi. In this study, the effects of single- and co-inoculation of Lactuca serriola with an arbuscular mycorrhizal (AM) fungus, Rhizoglomus intraradices, and endophytic fungi, Mucor sp. or Trichoderma asperellum, on plant growth, vitality, toxic metal accumulation, sesquiterpene lactone production and flavonoid concentration in the presence of toxic metals were evaluated. Inoculation with the AM fungus increased biomass yield of the plants grown on non-polluted and polluted substrate. Co-inoculation with the AM fungus and Mucor sp. resulted in increased biomass yield of plants cultivated on the polluted substrate, whereas co-inoculation with T. asperellum and the AM fungus increased plant biomass on the non-polluted substrate. In the presence of Mucor sp., mycorrhizal colonization and arbuscule richness were increased in the non-polluted substrate. Co-inoculation with the AM fungus and Mucor sp. increased Zn concentration in leaves and roots. The concentration of sesquiterpene lactones in plant leaves was decreased by AM fungus inoculation in both substrates. Despite enhanced host plant costs caused by maintaining symbiosis with numerous microorganisms, interaction of wild lettuce with both mycorrhizal and endophytic fungi was more beneficial than that with a single fungus. The study shows the potential of double inoculation in unfavourable environments, including agricultural areas and toxic metal-polluted areas. Electronic supplementary material The online version of this article (10.1007/s00572-018-0819-y) contains supplementary material, which is available to authorized users.

To improve the efficiency of Ni phytoextraction, the metal hyperaccumulator N. goesingensis was subject to treatment with a combination of a Ni uptake stimulating microorganism and the commercially available, IAA- based biostimulating seaweed extract - Kelpak. Additionally, we compared the plant growth promoting and Ni uptake capabilities of the two biofertilizers. Treatment with the Kelpak alone had no significant effect on plant growth or Ni accumulation. Inoculation of N. goesingensis with Phomopsis columnaris significantly improved the biomass of the hyperaccumulating plant and Ni yield per plant and improved several plant biometric features such as fresh and dry weight and several others related to leaf and root size. However, the combination of the two treatments yielded the best results; plants treated with the two growth promoting agents yielded 85% more biomass compared to not treated plants and accumulated 48% more Ni per plant. To verify plant inoculation with the fungus we generated a GFP expressing strain of P. columnaris and visualized the fungus in both plant leaves and roots. To trace the development of the fungus in planta and to evaluate the effect of biostimulant treatment on mycelium development fungal translational elongation factor 1α (tef1α) DNA was quantified with qPCR. Upon biofertilizer the abundance P. columnaris in plant leaves increased nearly 5-fold. The utilization of plant growth stimulating microorganisms, endophytic fungi in particular, can significantly improve Ni phytoextraction in hyperaccumulator N. goesingensis., This work was supported by The National Centre for Research and Development, Poland, project AGRONICKEL (contract No. FACCE SURPLUS/I/AGRONICKEL/02/2016).

Sixteenth-century Arrases from the Krakow Royal Castle constitute a Polish national cultural heritage; hence, they should be under special protection. The storage of historic objects at strict temperature and humidity conditions is fundamental for their protection against microorganisms. However, sometimes active preservation must be applied to disinfect bio-contaminated objects. In this study, 39 strains of microorganisms, both fungi and bacteria, isolated from Arrases deposited in the Wawel warehouse were isolated and then identified using molecular tools. Fungal ability to colonize and degrade silk and wool laboratory samples was studied. Selected microbial strains were compared concerning their ability to affect silk fibroin using size-exclusion chromatography (SEC). The effectiveness of low-temperature helium-generated plasma in disinfecting the model wool and silk samples inoculated with selected strains was tested. The results showed that plasma, despite its high biocidal activity in the case of paper, was not effective on porous textile materials. The alternative protection mechanism, involving active packaging in the form of textiles impregnated with silver-exchanged zeolites, could be used to separate layers of rolled tapestries in the warehouse. Nevertheless, optimal temperature and humidity conditions should be strictly maintained and controlled.

This present paper studies the response of Anthyllis vulneraria-Rhizobium symbiosis to heavy metal stress. The symbiotic rhizobium bacteria isolated from root nodules of A. vulneraria from zinc and lead wastes were examined in this project. Light microscopy (LM) and transmission electron microscopy (TEM) were used to analyze the nodule anatomy and ultrastructure and conduct a comparison with nonmetal-treated nodules. 16S ribosomal DNA sequence analysis of bacteria isolated from metal-treated nodules revealed the presence of Rhizobium metallidurans and Bradyrhizobium sp. In regard to heavy metal resistance/tolerance, a similar tolerance to Pb was shown by both strains, and a high tolerance to Zn and a lower tolerance to Cd and Cu by R. metallidurans, whereas a high tolerance to Cd and Cu and a lower tolerance to Zn by Bradyrhizobium were found. The nodules of Anthyllis from metal-polluted tailing sites were identified as the typical determinate type of nodules. Observed under TEM microscopy changes in nodules ultrastructure like: (1) wall thickening; (2) infection thread reduction; (3) vacuole shrinkage; (4) synthesis of phenolics in vacuoles; (5) various differentiation of bacteroids and (6) simultaneous symbiosis with arbuscular mycorrhiza fungi could be considered as a form of the A.vulneraria-Rhizobium symbiosis adaptation to metal stress.

Over the last years the role of fungal endophytes in plant biology has been extensively studied. A number of species were shown to positively affect plant growth and fitness, thus attempts have been made to utilize these microorganisms in agriculture and phytoremediation. Plant-fungi symbiosis requires multiple metabolic adjustments of both of the interacting organisms. The mechanisms of these adaptations are mostly unknown, however, plant hormones seem to play a central role in this process. The plant hormone strigolactone (SL) was previously shown to activate hyphae branching of mycorrhizal fungi and to negatively affect pathogenic fungi growth. Its role in the plant–endophytic fungi interaction is unknown. The effect of the synthetic SL analog GR24 on the endophytic fungi Mucor sp. growth, respiration, H2O2 production and the activity of antioxidant enzymes was evaluated. We found fungi colony growth rate was decreased in a GR24 concentration dependent manner. Additionally, the fungi accumulated more H2O2 what was accompanied by an altered activity of antioxidant enzymes. Symbiosis with Mucor sp. positively affected Arabidopsis thaliana growth, but SL was necessary for the establishment of the beneficial interaction. A. thaliana biosynthesis mutants max1 and max4, but not the SL signaling mutant max2 did not develop the beneficial phenotype. The negative growth response was correlated with alterations in SA homeostasis and a significant upregulation of genes encoding selected plant defensins. The fungi were also shown to be able to decompose SL in planta and to downregulate the expression of SL biosynthesis genes. Additionally, we have shown that GR24 treatment with a dose of 1 μM activates the production of SA in A. thaliana. The results presented here provide evidence for a role of SL in the plant–endophyte cross-talk during the mutualistic interaction between Arabidopsis thaliana and Mucor sp.

Context The requirement for rebuilding forecrop stands besides replacement of meadow vegetation with forest plants and formation of soil humus is the presence of a compatible ectomycorrhizal (ECM) fungal community. Aims This study aims to assess ectomycorrhizal fungi diversity associated with silver fir (Abies alba Mill.) seedlings regenerating in silver fir stands and Scots pine forecrops. Methods One-year-old seedlings were sampled in six study sites: three mature fir forests and three pine forests. ECM fungi were identified by polymerase chain reaction amplification and sequencing of the internal transcribed spacer of rDNA. Results The mean mycorrhizal colonization exceeded 90 %. Thirty-six ectomycorrhizal taxa were identified in fir stands and 23 in pine forecrops; ten out of these species were common to both stands. The fungal communities were different between study sites (R = 0.1721, p = 0.0001). Tomentella stuposa was the only species present at all sites. Conclusion Silver fir seedlings in Scots pine forecrops supported smaller ECM fungal communities than communities identified in mature silver fir stands. Nevertheless, fungal colonization of seedling roots was similar in both cases. This suggests that pine stands afforested on formerly arable land bear enough ECM species to allow survival and growth of silver fir seedlings.

Microbiological deterioration was observed on a historic collection of retouched glass plate negatives. The collection came from a burnt manor house that belonged to the Brandys family before World War IInd. The photographs were taken at the end of 19th century. The collection consists of 35 glass plate negatives, 4 of which were examined for possible presence of microorganisms. The current state of the negatives indicated that the collection may have been flooded. Initially, the viability of the microorganisms on the plates was examined using luminescence adenosine phosphate assay. The fungi were isolated and identified with molecular biology methods as Trichoderma longibrachiatum, Hypocrea lixii, Aspergillus versicolor, Penicillium sp. As the historic negatives were covered with a protective varnish layer, the impact of the isolated fungi on test negative plates covered with dammar and sandarac varnishes, and on a gelatine image layer were examined. The most effective in degradation of gelatine emulsion was T. longibrachiatum. All of the investigated microorganisms quickly decomposed silver image in gelatine layer not covered with varnish in opposite to slower decomposition of silver image in gelatine layer covered with sandarac and dammar varnishes. UV-induced luminescence observation confirmed that the microorganisms quickly decomposed gelatin layer not covered with varnish. The cracking of varnish was the result of fungal activity within gelatin, however, some fungi also attacked the varnish itself.

The current distribution of Tricholoma ustaloides Romagn. in Poland is presented, based on literature data and the results of mycological investigations in oak-hornbeam forest associations in the Kotlina Raciborska basin. The paper reports the morphology of the discovered basidiomata, the habitat where they were found, and ITS sequence data for the specimens, and briefly discusses similar species and the ecology of the presented fungus. The location given in the paper is currently the only known station of T. ustaloides in Poland. The importance of secondary habitats for survival of this taxon is stressed.

We investigated the influence of the predatory fungus Zoophagus sp. and temperature on the number of rotifers inhabiting activated sludge. When a sample of sludge was subjected to the fungus, the number of Lecane inermis and bdelloid rotifers was reduced at 15 °C and 20 °C, whereas at 8 °C the effect was not significant. The effect of Zoophagus on two Lecane and one bdelloid species, in conditions optimal for rotifers, confirmed the negative effect of the fungus on rotifer density. In the L. inermis treatment, the number of living rotifers was three times lower than in the control. These results demonstrated that the massive occurrence of predatory fungus may endanger the population of rotifers (organisms considered capable of significantly improving the quality of the effluent from wastewater treatment plants).

Improving the nutritional value of commonly cultivated crops is one of the most pending problems for modern agriculture. In natural environments plants associate with a multitude of fungal microorganisms that improve plant fitness. The best described group are arbuscular mycorrhizal fungi (AMF). These fungi have been previously shown to improve the quality and yield of several common crops. In this study we tested the potential utilization of Rhizophagus irregularis in accelerating growth and increasing the content of important dietary phytochemicals in onion (Allium cepa). Our results clearly indicate that biomass production, the abundance of vitamin B1 and its analogues and organic acid concentration can be improved by inoculating the plant with AM fungi. We have shown that improved growth is accompanied with up-regulated electron transport in PSII and antioxidant enzyme activity.

Main conclusion According to the results presented in this paper the fungal endophyteEpichloë typhinasignificantly improves the growth, PSII photochemistry and C assimilation efficiency of its hostDactylis glomerata. In this paper, we present a comprehensive study of the impact of the endophytic fungi Epichloë typhina on its plant hosts’ photosynthesis apparatus. Chlorophyll a fluorescence, gas exchange, immuno-blotting and spectrophotometric measurements were employed to assess photosynthetic performance, changes in pigment content and mechanisms associated with light harvesting, carbon assimilation and energy distribution in Dactylis glomerata colonized with Epichloë typhina. According to the results presented in this study, colonization of D. glomerata results in improved photosynthesis efficiency. Additionally, we propose a new mechanism allowing plants to cope with the withdrawal of a significant fraction of its energy resources by the endophytic fungi. The abundance of LHCI, LHCII proteins as well as chlorophyll b was significantly higher in E+ plants. Malate export out of the chloroplast was shown to be increased in colonized plants. To our knowledge, we are the first to report this phenomenon. Epichloë colonization improved PSII photochemistry and C assimilation efficiency. Elevated energy demands of E+ D. glomerata plants are met by increasing the rate of carbon assimilation and PSII photochemistry. Electronic supplementary material The online version of this article (doi:10.1007/s00425-015-2337-x) contains supplementary material, which is available to authorized users.

Cichorium intybus (common chicory), a perennial plant, common in anthropogenic sites, has been the object of a multitude of studies in recent years due to its high content of antioxidants utilized in pharmacy and food industry. Here, the role of arbuscular mycorrhizal fungi (AMF) in the biosynthesis of plant secondary metabolites and the activity of enzymatic antioxidants under toxic metal stress was studied. Plants inoculated with Rhizophagus irregularis and non-inoculated were grown on non-polluted and toxic metal enriched substrata. The results presented here indicate that AMF improves chicory fitness. Fresh and dry weight was found to be severely affected by the fungi and heavy metals. The concentration of hydroxycinnamates was increased in the shoots of mycorrhizal plants cultivated on non-polluted substrata, but no differences were found in plants cultivated on metal enriched substrata. The activity of SOD and H2O2 removing enzymes CAT and POX was elevated in the shoots of mycorrhizal plants regardless of the cultivation environment. Photochemical efficiency of inoculated chicory was significantly improved. Our results indicate that R. irregularis inoculation had a beneficial role in sustaining the plants ability to cope with the deleterious effects of metal toxicity.

The diversity of ECM communities of 1-year-old silver-fir seedlings regenerating in mature silver-fir stands is significantly higher than in neighboring larch forecrops. Forecrop stands provide the necessary shade for shade preferring seedlings, such as silver-fir, which cannot be introduced as the first generation in open areas. Larch is a good candidate, recommended to be utilized as forecrop. Since fungal symbionts of Abies alba seedlings regenerating under larch canopy have not been investigated, we aimed to evaluate the diversity of ECM of 1-year-old silver-fir seedlings regenerating under canopy of larch and to compare these communities to those found in adjacent mature silver-fir stands. Three silver-fir stands (F) and three European larch forecrops (L) were selected to study. Seedling size did not differ between F and L stands. ECM colonization was observed in 100% silver-fir seedlings in F and 80% in L stands. The fine roots were highly colonized, and 91 and 87% of live ECM were found in seedlings from F and L stands, respectively. Sequencing analysis revealed a total 53 ECM taxa. The observed number of ECM taxa in the F stands was significantly higher (46) than that in the L forecrops (25), and 34% of taxa were common to both stands. The dominant ECM species in F were unidentified fungus 1, Piloderma sp., Tylospora asterophora and Russula integra. Fir seedlings regenerating in L forecrops formed ectomycorrhizas mostly with unidentified fungus 1, Tomentella sublilacina, Tylospora sp., Hydnotrya bailii and T. asterophora. Based on ANOSIM analysis, ECM communities have shown significant differences between study sites. The diversity of ECM fungal partners and the high colonization rate of silver-fir seedlings regenerating in larch forecrop stands should be sufficient to provide efficient afforestation of post-arable lands and gives the opportunity for their successful rebuilding.